Modeling and Data Analysis 📊 | Fall 2025

Name: Modeling and Data Analysis
Author: Lucy Lai

How can we use models and data to understand and predict the world around us?

Lucy Lai

Hi everyone, I’m a new faculty member at UCSD and excited to be teaching COGS 109 this quarter! In this course, we’ll explore different ways to model and understand data, while building practical skills that are useful for research, industry, and beyond. You’re always welcome to come to my office hours to ask questions or just say hello. I’m looking forward to a great quarter together!

Important Course Info

TA	Jiesen Zhang
PLAs	Parinita Saha & Johny Nguyen
Reader	Zhicheng Wang
Lectures	MWF, 9-9:50am @ CENTR 113
Discussion	• W, 2-2:50pm @ WLH 2113 • F, 4-4:50pm @ WLH 2207 • F, 5-5:50pm @ WLH 2207

Office Hours

Prof. Lai	• W, 2:30-3:30 (walk-in), 3:30-4pm (book only) @ CSB 244/Zoom • Th, 4:30-5:30pm (book only) on Zoom
Jiesen Zhang	During all discussion sections (book for week 10)
Johny Nguyen	During W, 2pm discussion sections and W, 12-1pm on Zoom (book)
Parinita Saha	During F, 4pm discussion section and F, 3-4pm on Zoom (book)

Course Schedule

Week 0

Sep 26 (F)

LEC 0 Course overview and expectations 🎥: Slides

📖 Readings: ISLP Ch. 1

DISC No section this week

🚨 If you missed today’s class, please see this announcement

Week 1 — Intro to Statistical Learning

General

🛝 Week 1 — all slides

🚨 Week 1 Reminders

#FinAid Please submit this short survey to confirm student activity for the quarter! (Required for all students): Submit

Sep 29 (M)

LEC 1 What is statistical learning? 🎥: Slides

📖 Readings: ISLP Ch. 2.1

HW 1 released!: Details

💡 How to fix the webclicker issue

Oct 1 (W)

LEC 2 Assessing model accuracy 🎥: Slides

📖 Readings: ISLP Ch. 2.2

DISC 2pm @ WLH 2113: Slides

Oct 3 (F)

LEC 3 Data exploration 🎥: Slides

📖 Readings: ISLP Ch. 2.3

DISC 4pm & 5pm @ WLH 2207: Slides

Group project Guidelines and rubric released: Details

Quiz 1 released! due M, Oct 6 @ 11:59pm: Submit

Syllabus quiz due 11:59pm: Submit

Pre-course survey due 11:59pm: Submit

HW 1 due 11:59pm: Submit

Week 2 — Regression

General

📊 FINAL PROJECT GROUPS 📊

🛝 Week 2 — all slides

💡Resources:

Week 1&2 webclicker questions — use me to study for exams!

Exam question bank — use me to study for exams!

Linear regression modeling workflow

Models notes template — use me to follow along in lecture!

Models overview notes template — use me as a learning tool!

Common statistical tests are linear models!

🚨 Week 2 - Monday reminders

🚨 Week 2 - Friday reminders

Oct 6 (M)

LEC 4 Simple linear regression 🎥: Slides

📖 Readings: ISLP Ch. 3.1

Quiz 1 due 11:59pm: Submit

HW 2 released!: Details

Oct 8 (W)

LEC 5 Multiple linear regression 🎥: Slides

📖 Readings: ISLP Ch. 3.2

DISC 2pm @ WLH 2113: Slides

Oct 10 (F)

LEC 6 Other considerations in regression 🎥: Slides

📖 Readings: ISLP Ch. 3.3

DISC 4pm & 5pm @ WLH 2207: Slides

Quiz 2 released! (optional) due M, Oct 13 @ 11:59pm: Submit

HW 2 due 11:59pm: Submit

#FinAid due TODAY Please submit this short survey to confirm student activity for the quarter! (Required for all students): Submit

Week 3 — Classification

General

🛝 Week 3 — all slides

🚨 Week 3 - Monday reminders

🚨 Week 3 - Friday reminders

Oct 13 (M)

EXAM 1 covers Weeks 1 & 2

You may bring one 8.5x11” cheat-sheet, one-sided

To prepare: review HW 1&2, Quiz 1&2, webclicker questions from Week 1&2, check out the exam question bank.

HW 3 released!: Details

Quiz 2 (optional) due 11:59pm: Submit

Oct 15 (W)

LEC 7 Logistic Regression 🎥: Slides

📖 Readings: ISLP Ch. 4.1-4.3

Group project Checkpoint 1 due Mon, Oct 20: Submit video / Submit self-grade

DISC 2pm @ WLH 2113: Slides

Oct 17 (F)

LEC 8 Generative classification models 🎥: Slides

📖 Readings: ISLP Ch. 4.4

DISC 4pm & 5pm @ WLH 2207: Slides

Quiz 3 released! due Mon, Oct 20: Submit

HW 3 due 11:59pm: Submit

Week 4 — Resampling

General

🛝 Week 4 — all slides

🚨 Week 4 - Friday reminders

💡Resources:

Week 3&4 webclicker questions — use me to study for exams!

Oct 20 (M)

LEC 9 Cross-validation 🎥: Slides

📖 Readings: ISLP Ch. 5.1

Group project Checkpoint 1 due 11:59pm: Submit video / Submit self-grade

HW 4 released!: Details

Quiz 3 due 11:59pm: Submit

Oct 22 (W)

LEC 10 Bootstrap methods & predictive modeling workflow 🎥 (podcast audio error, please see this re-recorded lecture): Slides

📖 Readings: ISLP Ch. 5.2

DISC 2pm @ WLH 2113: Slides

Oct 24 (F)

LEC 11 Generative classification models (cont’d) & kNN 🎥: Slides

📖 Readings: ISLP Ch. 4.4 & 2.2

DISC 4pm & 5pm @ WLH 2207: Slides

Quiz 4 released! (optional) due Mon, Oct 27: Submit

HW 4 due 11:59pm: Submit

Week 5 — Model Selection & Regularization

General

🛝 Week 5 — all slides

🚨 Week 5 - Monday reminders

🚨 Week 5 - Friday reminders

Oct 27 (M)

EXAM 2 covers Weeks 3 & 4

You may bring one hand-written 8.5x11” cheat-sheet, one-sided

To prepare: review HW 3&4, Quiz 3&4, webclicker questions from Week 3&4, check out the exam question bank.

Quiz 4 (optional) due 11:59pm: Submit

HW 5 released! HW5 is very short ~2hrs with NO coding portion, because I want everyone to focus their coding efforts on their group checkpoint 2 this week! We will also address most of it directly in lecture.: Details

Oct 29 (W)